From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH] Revert "Input: trackpoint - add new trackpoint firmware ID" Date: Thu, 4 Jan 2018 16:56:59 -0800 Message-ID: <20180105005659.j2x56opkq74wm7v2@dtor-ws> References: <20171230152213.GA2099@marax.lan.yath.de> <20171231082646.GC25965@kroah.com> <901a0a66-eb83-9dcd-658c-5b09eabcab88@canonical.com> <20180102070811.p7gfaq3vr55sdbd3@dtor-ws> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pl0-f47.google.com ([209.85.160.47]:32986 "EHLO mail-pl0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751108AbeAEA5C (ORCPT ); Thu, 4 Jan 2018 19:57:02 -0500 Received: by mail-pl0-f47.google.com with SMTP id 1so2106662plv.0 for ; Thu, 04 Jan 2018 16:57:02 -0800 (PST) Content-Disposition: inline In-Reply-To: Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Aaron Ma Cc: Greg KH , Sebastian Schmidt , linux-input@vger.kernel.org Hi Aaron, On Tue, Jan 02, 2018 at 09:57:55PM +0800, Aaron Ma wrote: > No, it is not a regression of this commit. > > ThinkPad X1 Yoga 2nd: > trackpoint (ID: 01) > > ThinkPad X1 Yoga 3rd: > trackpoint (ID: 03) > > Both laptop's trackpoints have the same behavior. > Writing "speed" of sysfs is failed. > > Override the ID and force loading drivers/input/mouse/elantech.c, > it causes too many failure and trackpoint stops work. Right, because it does not support Elantech *touchpad* protocol, that is not a surprise. > > The ID of "2.4.18 READ SECONDARY ID (x"E1")" in TrackPoint specification > does not indicate any other vendors but only trackpoint. Exactly. If ID does not match, it is not an IBM trackpoint device. > Elantech uses 0x03e9. > ALPS uses 0x00e6/0x00e7/0x00ec. > > Maybe the windows tool's is wrong like Linux driver before. I am not sure what you mean by that. Anyway, I played with my Carbons a bit, and it seems that the patch should indeed be reverted. I believe that neither the Elantech nor ALPS trackpoints support the IBM trackpoint protocol; none of the extended features (sensitivity, inertia, etc) work when we register them as TTPS/2 devices. They should continue to be registered as "Generic PS/2" as that's that they support. I understand that you want scroll mode working with trackpoints, but forcing them to pretend that they are TTPS/2 devices is not the proper way of doing that. Write udev rules that would set ID_INPUT_POINTINGSTICK property on all input devices connected to a pass-through serio ports on LENOVO devices, and you should be set (just make sure you cover both PS/2 pass-through and RMI pass-through options). Thanks. -- Dmitry